The American sociologist William Graham Sumner (1840-1910) argues that free trade is not just a “theory” but another aspect or “mode” of the broader movement for liberty:
Now free trade is not a theory in any sense of the word. It is only a mode of liberty; one form of the assault (and therefore negative) which the expanding intelligence of the present is making on the trammels which it has inherited from the past. … Free trade is a revolt, a conflict, a reform, a reaction and recuperation of the body politic, just as free conscience, free worship, free speech, free press, and free soil have been. It is in no sense a theory.
About this Quotation:
William Graham Sumner was not only a founder of American sociology but an ardent free trader. He wrote an important history of tariffs in America as well as popular works on free trade for newspapers. In his book Protectionism: the -ism which teaches that waste makes wealth (1888) was written at a time when free trade was under attack, when it was rejected by “practical”men of business and politics who dismissed it as “mere theory.” Interestingly, Bastiat was met with the same criticism by protectionists 40 years earlier (see his article “Theory and Practice” (c. 1845). In this passage Sumner makes two important points. Firstly, that critics of free trade already live in a large country which has complete freedom of trade within its borders, hence he accuses them of hypocrisy for not arguing for tariff barriers between the states. Secondly, for not appreciating the fact that the free trade movement is like other historical movements for individual liberty such as for freedom of expression, freedom of religion, and the abolition of slavery. If free trade was only “mere theory”, then so were all these other movements which have greatly improved the lives of human beings.